Clemson quarterback Trevor Lawrence (16) hands the ball off to running back Lyn-J Dixon (23) during the first half of Saturday's game against Louisville in Louisville, Ky. Photo by Timothy D. Easley of The Associated Press

AP Top 25 voters are being tougher on Clemson than any preseason No. 1 team in 48 years.

The undefeated defending national champion Tigers are now No. 4 in The Associated Press college football poll presented by Regions Bank. Alabama was No. 1 in the Top 25 on Sunday, followed by LSU and Ohio State at No. 3. The point gap between Alabama and Clemson is 78 this week, the smallest margin between Nos. 1 and 4 this season.

Teams commonly give up the No. 1 ranking in the AP poll without losing. Most recently, in 2015, defending national champion and preseason No. 1 Ohio State dropped to No. 2 in November while getting to 10-0.

The year before, Florida State relinquished the No. 1 ranking a couple of times, dropping to No. 2 while remaining unbeaten until the College Football Playoff semifinal.

What makes Clemson's fall unusual is just how far the Tigers have dropped. The last time a preseason No. 1 took a similar tumble while winning all its games was 1971, when Notre Dame dropped all the way to No. 7 while starting 5-0.

Clemson slipped to No. 2 at the end of September after pulling out a one-point win at North Carolina. Alabama took the top spot after starting the season No. 2.

Clemson spent two weeks at No. 2 before getting jumped by LSU. The voters rewarded those Tigers for beating a highly ranked opponent (Florida) for the second time this season.

The latest dip by Clemson was the most surprising. Ohio State makes a good case for being the most dominant team in the country. The Buckeyes lead the nation -- by a lot -- in scoring margin at 41.7. Their latest rout was 52-3 on Friday night at Northwestern. Clemson, though, was also coming off an easy victory, 45-10 at Louisville on Saturday.

"We can't even get a seat on the Roy (rest of y'all) bus anymore. They kicked us off," Clemson coach Dabo Swinney told reporters Sunday. "Hopefully, we don't only win by five touchdowns again next week. Might drop out of the polls."

Reality Check has been touting Ohio State as under-ranked for weeks and was also fine with giving LSU a bump up because of its victories against Texas and Florida. No argument here in dropping Clemson. No. 4 seems about right. The timing was odd.

It certainly sounds like Swinney is happy to use the slight to motivate a team that probably won't be challenged much by its competition.

One thing is for sure: When the College Football Playoff started in 2014 there was some concern the AP Top 25 would influence the committee's rankings, which don't start until around Halloween. Instead, it seems the opposite is happening and the AP voters have become more aggressive in moving top teams from week-to-week like the committee. Whether that is good, bad or neutral depends upon your favorite team's ranking.

No. 1 Alabama (7-0)

Next: vs. Arkansas

Reality check: Tua Watch is on: How healthy will QB Tua Tagovailoa (right ankle) be when the Crimson Tide plays LSU in three weeks?

Ranked: Little high, and that has nothing to do Tagovailoa's injury.

No. 2 LSU (7-0)

Next: vs. No. 9 Auburn.

Reality check: The Tigers' defense ranks 24th in the country at 4.72 yards per play allowed. Pretty good. However, counting just games against Power Five competition, LSU is allowing 5.54 yards per play, 68th in FBS.

Ranked: Too low. Best resume, though maybe not best team.

No. 3 Ohio State (7-0)

Next: vs. No. 13 Wisconsin.

Reality check: So many weapons for QB Justin Fields: Two running backs averaging 7 yard per carry. Five receivers with double-digit receptions and multiple touchdowns.